The present invention relates to a disk drive unit and is suitably applied to a floppy disk drive unit, for example.
Conventional disk drive units include a floppy disk drive in which a floppy disk, having a magnetic disk encased in a disk casing, is placed to write information to or read information from it.
More specifically, in a floppy disk drive unit 1 as illustrated in FIG. 1, a floppy disk 3 is inserted into the disk drive 4 through a disk inlet 5. Simultaneously, the disk detecting switch is turned on to indicate the insertion of the floppy disk 3.
The disk detecting switch is provided within the disk drive 4 and is activated by a bottom surface 3B of a disk casing 3A of the floppy disk 3 when the floppy disk 3 is inserted to a driven position within the disk drive 4. As a result, a signal representing the insertion of the floppy disk 3 is sent to a control unit provided in the disk drive 4. Thus, the disk drive 4 is actuated to drive the floppy disk 3, and at the same time an indication lamp 8 mounted on a front panel 7 is lit to indicate that the disc unit 1 is in operation.
The disk casing 3A of the floppy disk 3 has a write protect mode detection window 3C formed through it. The write protect mode detection window 3C is provided with a slidable closure tab 3D. When the floppy disk 3 is placed in the disk drive 4 with the write protect mode detection window 3C closed with the closure tab 3D, the disk detecting switch 4 is pushed to turn on to send a drive signal to the control unit, so that the disk drive 4 is actuated.
On the other hand, when the closure tab 3D is slid to open the write protect mode detection window 3C, the disk detecting switch is not turned on by placing the floppy disk 3 in the disk drive 4, and hence the disk drive 4 is not actuated and is placed in write protect mode.
In the floppy disk 3, the disk casing 3A has an indicating hole which indicates the storage capacity of the magnetic disk contained in the disk casing 3A.
More specifically, in a 2MB (megabytes) floppy disk 11 as shown in FIG. 2, a 2MB indication hole 11H is formed in a lower right corner 11F of the disk casing 11A parallel to the lower side 11D while a write protect mode detection window 11C is provided in a lower left corner 11B.
When the floppy disk 11 is placed in position in the disk drive 4, a 2MB detection switch which is provided to oppositely face the 2MB indication hole 11 is not pressed, and hence the control unit judges that the floppy disk 11 is a 2MB medium.
In a 4MB floppy disk 12 as shown in FIG. 3, a 4MB indication hole 12H is formed through the disk casing 12A at a position closer to the upper side than the position where the 2MB indication hole 11 of the 2MB floppy disk 11 (FIG. 2) is formed.
Thus, when the floppy disk 12 is placed in position in the floppy disk drive 4, a 4MB detection switch which is provided at a position to oppositely face the 4MB indication hole 12H is not pressed, so that the control unit determines that the floppy disk 12 is a 4MB medium.
The floppy disk 3 has a storage capacity of 1MB and is provided with neither the 4MB detection hole nor the 2MB detection hole. When the floppy disk 3 is placed in the disk drive 4, both 4MB and 2MB detection switches are activated, and thereby the control unit judges that the floppy disk 3 is a 1MB medium.
In the disk drive 4, floppy disks inserted is thus discriminated in storage capacity according to the operation mode of each of the 2MB and the 4MB detection switches.
The disc unit 1 is further provided with a disk detecting switch to detect the insertion of the floppy disk in addition to the storage capacity detection switches and the write protect mode detection switch. These disk switches detect information of floppy disks inserted.
The disc unit 1 is enhanced in operability by reducing in its size. However, the disk switches make the disk drive 4 rather complicated and increase the size of the disk drive 4.